1. Field of the Invention
The present invention relates generally to transport platforms for transporting cargo on container ships, and more specifically to open transport platforms which are configured for transporting oversized cargo such as vehicles/equipment and the like that cannot fit onto currently available transport platforms, and which are configured to permit vehicles to roll on and off without the need of additional structures such as ramps and the like.
2. Description of the Related Art
Open transport platforms, which have been used to transport vehicles or the like, have usually, due to their configuration and limited structural strength, been left to last during the loading process so that they can be placed on top of the uppermost containers on the deck of the container ship. That is to say, due to the limited ability of the platforms to bear large vertically acting loads such as those generated by the placement of a fully laden container on top thereof, the platforms have had to be disposed at the very tops of the container stacks. This, of course, severely limits both their utility and the number of platforms which can be carried on any one vessel.
A further drawback that open transport platforms suffer from is that, in order to have sufficient structural strength and durability, the platform and deck are relatively thick. Therefore, the ends of the platforms have a substantial vertical dimension and resemble a small vertically extending wall which juts up above the surface on which the platform is resting. The height of this end wall which can be about 24″ for example, tends to be such that only wheels having large diameter can readily roll up and over the end of the platform, and then later roll off the end of the platform without noticeable impact. Accordingly, it is therefore usually necessary to either use cranes to lift the cargo into place, or provide ancillary pieces of equipment such a ramp or ramps in order to allow wheeled vehicles to smoothly roll on and off the end of the platform during unloading/unloading.
This, of course, reduces the utility of the platform in that additional/ancillary equipment which is in itself heavy must either be carried with the platform, adding to its dead weight and complexity, or alternatively some means for moving the ancillary equipment about, such as fork lift of the like, must also be provided at both the site where the vehicles are loaded and the site wherein the vehicles are unloaded. In the case of a military operation (for example), it is often such that conditions are less than favorable and in the case of war or the like, the availability of ramps and fork lifts cannot be guaranteed and the daunting task of manually moving such heavy pieces of equipment from platform to platform may be too much should sufficient man-power (for example) not be available.
In addition to the above shortcoming, open transport platforms have suffered from the drawback that the holds of modern container ships are usually constructed to receive predetermined sized containers which are usually 40′×8′ long ISO (International Standards Organization) containers. These holds have bulkheads at each end which extend laterally from port to starboard. These bulkheads are each provided with vertically extending cell guides that are sized to permit the 40′×8′ ISO sized containers to be slid down between T-shaped guide members which define the cell guides, and thus be securely held at each end thereby.
With this construction, the containers can be secured against both rolling and pitching of the container ship. That is to say, disposition of 40′ containers between the bulkheads, which are spaced by about 40′, prevents fore-aft movement of the containers due to pitching of the vessel during transit, while the engagement of the ends of the containers with the T-guides prevents lateral movement (port/starboard movement) due to rolling of the vessel. It should be noted that it is also possible with this type of arrangement to dispose two 20′ ISO containers in an end-to-end arrangement, between the bulkheads.
After a hold is filled with the above-mentioned types of ISO containers, a hatch is placed over the top to close the hold. Containers are then stacked on top of the hatches.
However, it has been extremely difficult, if not impossible, to dispose anything but the 40′×8′ ISO containers in the holds, and attempts to dispose transport platforms below deck have not met with success. Thus, storage in such holds has been limited to the above mentioned 40′×8′ ISO containers which are dimensioned to fit in the cell guides. This means that off-sized containers or platforms, which are either wider or narrower than the width of the cell guides, cannot be secured below deck in the holds and are relegated to possible disposition above deck.
As will be readily understood, in many instances it is highly desirable to store cargo which is being carried on an open transport platform, below deck so as to enclose same and thus limit the amount of exposure to the elements during shipping.